


Lines in the Sand

by A_Thousand_Skies (cywscross)



Series: Dr. Stone Oneshots [3]
Category: Dr. STONE (Anime), Dr. STONE (Manga)
Genre: Alternate Canon, Don't copy to another site, Established Relationship, F/M, Fluff, Late Night Conversations, M/M, Multi, Negotiations, Polyamory
Language: English
Status: Completed
Published: 2019-11-11
Updated: 2019-11-11
Packaged: 2021-01-27 11:56:42
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 2,439
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21391759
Author URL: https://archiveofourown.org/users/cywscross/pseuds/A_Thousand_Skies
Summary: Even in the Stone World, there are lines Senkuu won't cross, but prioritizing anything above his friends' lives won't ever be one of them, even if it means getting his hands dirty.
Relationships: Asagiri Gen & Kohaku, Asagiri Gen/Ishigami Senkuu, Asagiri Gen/Ishigami Senkuu/Kohaku, Ishigami Senkuu & Saionji Ukyou, Ishigami Senkuu/Kohaku
Series: Dr. Stone Oneshots [3]
Series URL: https://archiveofourown.org/series/1542208
Comments: 9
Kudos: 156





	Lines in the Sand

**Author's Note:**

> For the [100prompts challenge on DW](https://100prompts.dreamwidth.org/).
> 
> [**Prompt:** 041\. Words](https://cywscross.dreamwidth.org/17140.html)
> 
> [Cross-Posted from Tumblr](https://a-stone-world-saga.tumblr.com/post/188923648886/senkuu-talks-a-good-game-a-war-without-bloodshed)

Senkuu talks a good game - _a war without bloodshed_ \- and it’s good for morale, but when Ukyou’s condition for siding with them is winning the war without a single life lost, Senkuu cannot in good conscience promise that.

War never ends without death. Tsukasa alone has already killed hundreds, if not thousands, and he and Hyouga combined are practically two armies on their own. To think the Kingdom of Science can confront them _while holding back_ in any way is idealistic at best and suicidal at worst.

Besides, Senkuu cannot dismiss the possibility that it might come down to killing an enemy in order to save one of his. He doesn’t want it to, of course not, but the _possibility_ is there, and a lifetime ago, Senkuu _electrocuted_ the bullies who beat Taiju up when that big oaf charged in to try and protect him. Senkuu was _nine _at the time.

Now he’s twice that some days and four hundred times that on worse days, but that part of him has never changed - nobody touches what’s his and walks away from it without paying tenfold.

(Besides, Tsukasa _literally killed him_, and that alone wouldn’t be so bad, but he’d also scared Yuzu, _threatened_ her, most likely would’ve killed her _and_ Taiju if they hadn’t managed to get away, and surely that’s enough grounds for taking off the kid gloves.)

So when Ukyou asks, when he gives them an ultimatum that could very well be their death sentence, Senkuu looks him in the eye and says _no_.

“I can promise that my first option won’t ever be to march in and kill everyone who opposes us,” Senkuu says bluntly, ignoring the sudden hush around him as he stares unblinkingly at the visibly startled archer in front of him. “And I can promise that we’ll try our best to keep casualties to a minimum.”

His jaw clenches, and his spine stiffens. He thinks of all the people who’ve helped him get this far, who believed in him and his science on little more than faith. And he thinks of Yuzu and Taiju, deep in the enemy’s camp, and when it comes down to it, this was never up for debate.

“But I will also promise that nothing is more important than _my people_ coming out on the other side of this war alive and in one piece, and if that means assholes like Hyouga and Tsukasa have to die, then I would _cut their heads off myself_.”

He glares hard at Ukyou, and the man twitches like he wants to take a step back. Senkuu isn’t surprised. He doesn’t get angry often, but a part of him _seethes_ now at the very idea of someone thinking he should place the lives of those aiming to _slaughter most of them_ and _subjugate the rest_ on equal footing with the lives of those under Senkuu’s protection.

He doesn’t believe that all adults of the modern era should be wiped out for past sins, real or imagined, nor does he believe that the weak or foolish or whoever else doesn’t meet Hyouga’s standards should be eliminated. But he also doesn’t believe in equality for all. He is not that kind.

Outsiders who attempt to harm any of the people in Senkuu’s kingdom - the people he now has a duty to to place _first_ \- will never be equal to those who are.

“We could definitely use someone with your skills,” Senkuu admits, forcibly curbing his rage and tucking it behind something more laidback. “But even if we couldn’t, I don’t think you should go back to Tsukasa, and not just because having you as an enemy too would suck.”

He can still feel Tsukasa’s hands on his neck, even now. At the end of the day, no matter what aspirations he believes he’s working towards, the truth of it is - anyone Tsukasa can’t control must be killed, whether or not they fit his pure-hearted youth criteria.

“You’re free to stay,” He continues steadily. “And if you don’t want to help, nobody here will force you. But I won’t promise you what you want, and if that’s not something you can live with, then we’re going to have to go our separate ways here.”

Ukyou stares back for a long, disquieting moment. Senkuu can feel Kohaku at his back though, ready to strike, as reassuring a presence as always.

“You’d let me leave though?” Ukyou says at last, and there’s an odd note in his voice, some emotion Senkuu can’t name right away. “Go back to Tsukasa if I wanted to? Just like that?”

Senkuu shrugs, inwardly swearing. He doesn’t know Ukyou well enough to bribe him with some kind of science, and the only thing he’s asked for so far isn’t something Senkuu can grant. Losing a talent like Ukyou here wouldn’t be a devastating loss, but it’ll probably come back to bite them in the ass one day.

Still.

“You haven’t done anything yet,” Senkuu tells him. “Well I mean you kidnapped Chrome, but you returned him too, so we’ll call us even on that front. I don’t go after people for not doing anything, even if I think they’re making shitty life choices.” He narrows his eyes. “But if you go, and then you come back on Tsukasa’s orders or Hyouga’s orders or anyone else’s orders and try to shoot someone here-”

“-then I will slit your throat myself,” Kohaku finishes, finally shouldering forward to stand beside Senkuu. Her glare is much more intimidating than anything Senkuu could probably manage.

He smirks and jerks his chin at her. “So she says. I wouldn’t test her; she usually follows up.”

Kohaku grins, all teeth and no humour. She still hasn’t drawn her blade, but her hand is very obviously resting on the hilt, and nobody with half a brain cell would doubt her conviction in that moment.

Surprisingly, Ukyou only glances briefly at her before looking back at Senkuu again. It doesn’t seem like he’s dismissing her, but somehow, the tense line of his shoulders actually _relaxes_.

Senkuu cocks an eyebrow. He exchanges a fleeting glance with Kohaku, who’s obviously seen the same thing, and neither of them lets their guard down, until-

“I can live with that,” Ukyou concedes with only a brief grimace. “I don’t want anymore people to die, but I... I wouldn’t want you to lose any of your friends just because of that either. That’s more important. So long as you really _try_, that’s good enough for me.” He straightens, one hand coming up to touch the bow slung over his shoulder. “And of course I’ll help, if I can. Just tell me where you want me.”

Senkuu’s other eyebrow joins his first. He rakes a critical eye over Ukyou but he can’t sense a lie. “...Quick change of heart, huh?”

It’s Ukyou’s turn to shrug. His gaze slides briefly to the side, in the general direction of Tsukasa’ empires miles away, and when he meets Senkuu’s eyes again, there’s something defiant in the tilt of his chin and the resolute set of his expression.

“You’d let me leave,” He says simply. “So I’m staying, and I want to help.”

Senkuu studies him for a few seconds more and even glances over his shoulder at Gen - who nods ever-so-slightly - just to make sure, before finally letting the tension drain out of his body.

Well, it looks like he hasn’t lost this battle after all.

He looks over at Kohaku, who frowns a little but slowly eases her hand from her katana.

Senkuu turns back to Ukyou with a more genuine smirk this time. “Alright, welcome then. If you’re serious about that help, best be prepared to work your ass off.”

“He’s a total slave-driver,” Kohaku agrees with a sigh, twisting easily out of the way of the elbow Senkuu half-heartedly throws at her, and as if their banter was the cue everyone else was waiting for, they surge forward, Chrome beaming as he sidles up beside the archer - _does that count as Stockholm syndrome?_ Senkuu wonders - Ginrou bouncing forward to poke nosily at Ukyou’s bow and arrows, Kinrou behind him, more suspicious but willing enough to give the newcomer a chance, and even Suika ventures forward curiously.

Senkuu falls back, snorting a little at the surprised, slightly overwhelmed look on Ukyou’s face as he’s more or less mobbed. Kohaku joins him, their shoulders bumping as they wander back to the lab, and Gen falls into step on his left a moment later.

“I’m still keeping an eye on him,” Kohaku grumbles. “He _kidnapped Chrome_.”

“He was telling the truth,” Gen tacks on lightly. “But it wouldn’t hurt to make sure.”

Senkuu hums his agreement. He’s pretty sure Ukyou won’t betray them, but precautions exist for a reason.

“I didn’t expect you to say all that,” Kohaku says abruptly, and both Senkuu and Gen glance over at her. She has her head tipped back, staring up at the sky.

“Do you disapprove?” Senkuu asks, though he’s pretty sure she doesn’t.

“Of course not,” Kohaku scoffs. “They threatened Ruri-nee and my home. I would kill them for that alone.”

“Oh?” Gen smirks, looking entertained. “Are there additional reasons you would kill them?”

Kohaku shoots him an arch look. “Obviously, that long-haired man can’t be allowed to destroy Senkuu’s Kingdom of Science either. We’ve put too much work into it, you know.”

“That’s true,” Gen agrees, voice gone excessively mournful. “I almost died making electricity the first time.”

Senkuu rolls his eyes at both of them. “Don’t be so dramatic. I feed you, don’t I?”

“Your ramen leaves a lot to be desired,” Gen huffs. “And your cola isn’t that great either.”

They reach the lab, and Senkuu pushes the curtain aside before waving them through. “I could stop, if you hate it so much?”

Gen pouts as he ducks inside. “...I suppose the cola’s not so bad.”

“And I love the ramen,” Kohaku adds as she ducks past him as well. “So you can’t stop, Senkuu.”

There’s a deeper meaning there, a weight in each word despite the lightness of her voice, and when Senkuu looks from Kohaku to Gen, their faces carry something equally determined.

Senkuu rocks back on his heels a little as he takes in the glass vials and beakers all around him, then smirks as his gaze returns to Gen and Kohaku. “Of course not. Our Kingdom of Science doesn’t fall that easily. Not with all of us here to keep it going.”

Kohaku grins, fierce and unwavering, and Gen smiles, less brazen but no less devoted.

Senkuu has always considered luck a fickle mistress. But even he can’t deny his good fortune when it comes to all the people who stand by him now.

“Okay then,” He rolls out the plans of their current military campaign. “Time to get the next phase rolling.” His hands slap against the surface of the table as he looks once more at Kohaku, at Gen. “We’re going to win, and we’ll ten billion percent bring everyone home alive.”

* * *

Later, at night, when he’s in the observatory because he can’t sleep, Gen’s dozed off beside him but Kohaku’s still awake, knees pulled up with her arms wrapped around them, leaning against Senkuu’s shoulder as they stare up at the stars.

“I didn’t expect you to say all that,” Kohaku repeats. “Earlier, with Ukyou.”

Senkuu hums noncommittally and watches her out of the corner of his eye. She has her hair down for once, and the spill of gold flutters against his arm whenever a new gust of wind rolls by.

“Problem?”

“You know it’s not that,” Kohaku huffs. “...I thought you were more like Ruri-nee. You have her self-sacrifice streak at least. I thought you would say something like ‘I’ll even let Tsukasa kill me if it’ll end the war peacefully’.”

Senkuu rolls his eyes. “First of all, that wouldn’t even work. Tsukasa would never leave people like Chrome or Gen or old man Kaseki alive. You too, you’re too much of a threat, can’t be controlled. And everyone else would have to acknowledge him as their king or whatever or they’d be killed too. And second of all, I don’t do self-sacrifice, I do _logic_. Is this about the sulfuric acid again?”

Kohaku’s head rolls back a little so that she doesn’t have to get off him to give him a pointed stare.

Senkuu sighs. “That was different. It was _science_, and sometimes, science demands a price. Evolution and progress usually do. Besides, it turned out fine in the end.”

His fingers twitch, bumping into Kohaku’s, and after a moment, he stretches a little to curl them around hers. Kohaku responds by simply flipping her hand and sliding their palms together.

“War is different,” He continues. “War is bloody and stressful and just ten kinds of fucked up. But war can also be predicted down to the smallest detail, and if we play it right, if we out-maneuver the enemy on every level possible, then at least we won’t have to pay for that.” He meets her gaze steadily. “I don’t plan on paying anything in this war. Tsukasa and Hyouga can shoulder that debt.”

Kohaku doesn’t immediately say anything after that. But after a few seconds of watching him with thoughtful eyes, she smiles at him the way she did the day they met, after she’d watched him build his pulley system to free her - a soft curve of her lips, quieter than her usual expressions but full of something warm and pleased.

“I agree,” She says, breaking eye-contact but only to settle more comfortably against him. Her hand tightens around his own. “Not coming home... is not an option. No matter what.”

Gen’s sleepy voice cuts in then. “I thought we cleared that up this afternoon, Kohaku-chan, Senkuu-chan. So can we _please_ get some rest? I hear war is exhausting enough without sleep-deprivation too.”

Kohaku snorts with laughter, and Senkuu sighs, but he obliges and nudges Kohaku onto her back before lying down himself and pulling their blankets up around their shoulders.

“Finally,” Gen mutters, wriggling around to cuddle into Senkuu, and then he’s out like a light again.

Kohaku yawns from Senkuu’s right before also curling into him. “I suppose Gen is right. Goodnight, Senkuu.”

She dozes off pretty quickly as well, and then Senkuu is the only one still awake. But he’s warm and comfortable between Gen and Kohaku, and for once, his head is quiet and not quite so cluttered.

His eyes slip shut before he knows it, and he doesn’t wake until morning calls.


End file.
